Charge Trapping in Semiconductor Photocatalysts: A Time- and Space-Domain Perspective.

Area of Science:

• Materials Science
• Photocatalysis
• Energy Conversion

Background:

• Solar energy utilization via photocatalysis is crucial for a sustainable energy economy.
• Photogenerated charge carrier dynamics, specifically charge trapping and recombination, dictate photocatalyst efficiency.
• Limited understanding of charge trapping, due to its complex temporal and spatial heterogeneity, hinders photocatalyst optimization.

Purpose of the Study:

• To elucidate the principles of advanced time- and space-resolved techniques for probing charge trapping in photocatalysts.
• To establish a direct link between charge trapping phenomena and photocatalytic activity.
• To review recent advancements in manipulating charge trapping for enhanced photocatalysis.

Main Methods:

• Femtosecond time-resolved transient absorption spectroscopy.
• Space-resolved microscopy techniques, including single-molecule fluorescence and surface photovoltage microscopy.
• Defect engineering for charge trap manipulation.

Main Results:

• Demonstration of advanced spectroscopic and microscopic methods for characterizing charge trapping.
• Overview of research utilizing these techniques to probe charge trapping mechanisms.
• Highlighting successful strategies for manipulating charge trapping via defect engineering.

Conclusions:

• Advanced time- and space-resolved techniques offer powerful tools for investigating charge trapping in photocatalysts.
• Understanding and controlling charge trapping is pivotal for optimizing photocatalytic performance.
• Future research should focus on further exploring defect engineering and its impact on charge dynamics for improved solar energy applications.